The present invention relates to a thrust reverser for a turbofan jet having a high bypass ratio in which the thrust reverser flaps are located on a jet engine cowling rearwardly of the turbofan cowling such that air passing over the outer surface of the jet engine cowling urges the thrust reverser flaps toward their forward thrust positions.
Turbofan-type turbojet engines are well known in the art and typically comprise a fan located at the front of the turbojet engine which directs a flow of bypass air through a duct bounded by the engine cowling on the inside and a fan cowling on the outside. The generally annular duct may channel both the bypass flow and the primary exhaust gas flow, or may channel only the bypass flow. In turbofan engines having high bypass ratios, typically the bypass duct channels only the bypass airflow from the turbofan.
In such applications, it is also known to provide a thrust reverser comprising a plurality of baffles or flaps which are movable between forward thrust positions and reverse positions in which the flaps redirect at least a portion the air emanating from the exit of the bypass duct in a direction so as to provide reverse thrust forces to the engine structure and the associated aircraft. In the forward thrust positions, the baffles or flaps are retracted so as to provide a smooth aerodynamic surface to the respective cowlings and to leave the exit of the bypass flow duct unobstructed to provide the optimum forward thrust. In some known types of thrust reversers, the movable baffles or flaps are located in the fan cowling, while in other types the baffles or flaps are located in the jet engine cowling. Typical known thrust reversers are disclosed in French Patents, 1,479,131; 2 625 261; and 2 650 861.
While these known thrust reversers have been generally successful, there exists a continuing need to reduce the complexity of such devices, reduce the width and bulk of the thrust reverser assembly, specifically regarding the outer diameter of the turbofan cowling to improve ground clearance, and to design such systems so as to facilitate access to the jet engine.